Mostly bonded rabbit passed yesterday. Need help with how to bond new rabbit

My sweet holand lop, Bun Bun, passed away unexpectantly yesterday. She was mostly bonded with a larger lop named Nudge. They were fine if there was a cage bar inbetween them and sometimes by themselves. They would groom each other and go to each other if they were scared. I don't want Nudge to get depressed so we are looking to get another bunny. Is there anything different about bonding this time around? Any tips are welcome!